buckle

1 to fall down or in as a result of physical pressure the flimsy bridge buckled under the weight of the caravan of trucks Synonyms collapse, cave (in), crumple, founder, give, go, go out, implode, tumble, yieldRelated Words deflate, flatten, melt, melt down; break, break down, conk (out), crash, die, fail, give out, stall; burst, shatter, smash, splinter, split; crack, crumble, pop, snapNear Antonyms inflate, rise, swell

2 to occupy (oneself) diligently or with close attention buckled himself down and finished the assignment in record time Synonyms address, bend, apply, devote, giveRelated Words readdress, reapply; knuckle down, set (to), settle (down); busy, commit, concern, engage, involve; exert, exhaust, put out, spend, strain, stress, tax, trouble, wear out; carry on, pitch in, plunge (in); grind, hump, hustle, peg (away), plod, plow, plug (away), workNear Antonyms dally, dawdle, dillydally, fiddle (around), fool around, idle, mess around, monkey (around), play, potter (around), putter (around), trifle